Apparatus for tying moving bundles



Dec. 8, 1964 B. H. BUNN APPARATUS FOR TYING MOVING BUNDLES 8 Sheets-Sheet 1 Filed May 6, 1963 fiz m Zmz:

BENJAMIN H BUNN Dec. 8, 1.964. ,B. H. BUNN APPARATUS FOR TYING MOVING BUNDLES 8 Sheets-Sheet 2 Fliled Ma 6 1963 kww I ma

BENJAMIN H BUNN B y. g 1 W W/21w, 651mm 05 dlttgs.

8 Sheets-Sheet 3 B. H. BUNN APPARATUS FOR TYING MOVING BUNDLES 27.15am 2:: BENJAMIN H. BUNN Dec. 8, 1964 Filed May 6, 1963 Dec. 8, 1964 B. H. BUNN 3,160,033

APPARATUS FOR TYING MOVING BUNDLES Filed May 6, 1963 8 Sheets-Sheet 4 BENJAMIN H. BUNN Dec. 8, 1964 B. H. BUNN APPARATUS FOR TYING MOVING BUNDLES 8 Sheets-Sheet 5 Filed May 6, 1963 BENJAMIN H BUNN Wm, 09am, (54am i 6W 2/6.

Dec. 8, 1964 B. H. BUNN APPARATUS FOR TYING MOVING BUNDLES 8 Sheets-Sheet. 6

Filed May 6, 1963 BENJAMIN H BUNN Dec. 8, 1964 B. H. BUNN APPARATUS FOR TYING MOVING BUNDLES 8 Sheets-Sheet 7 Filed May 6, 1963 .IEZET-Z :72:

BENJAMIN H BUNN Dec. 8, 1964 B. H. BUNN 6 APPARATUS FOR TYING MOVING BUNDLES Filed May 6, 1963 8 Sheets-Sheet 8 35251-2 2:: BENJAMIN H. BUNN 3,166,083 APPARATUS FOR TYENG MGVIR G EUNBLES Btiilaillil H. Eunn, Chicago, Eli, assignor to E. H. Benn Company, (Thicago, lllL, a corporation of lllinois Filed May 6, 1963, er. No. 278,31 Claims. {(Jl. "ital-7) This invention relates to a conveyorized system for tying bundles, such as stacks of envelopes containing mail, or the like.

For purposes of illustration, this invention will be described with reference to its application to the automatic conveyorized tying of bundles of envelopes and is adapted particularly for use in post omces. It is understood, however, that the invention can be used for tying any of the more commonly known twine tied bundles whether the bundles contain food, smaller bundles, sheets of material, or are boxes which are to be Wrapped with paper to be tied. It is desirable, however, that the system of this invention be used with articles which have generally similar shapes and sizes so that the various holding and conveying mechanisms used in the system may be of a uniform kind.

Tying machines are known which are designed for twine tying bundles of envelopes together with a long tie and a cross tie, the ties being either single or double wrap. in such machines the bundle of envelopes to be tied is first assembled and oriented in a given fashion by hand to form a generally rectangular bundle, and is then placed on a tying machine which, when set in operation, effects either a long tie only or ties successively a long tie and a cross tie around the bundle, after which the bundle is removed from the tying apparatus. Normally, such a machine requires an operator for each machine, who physically places the bundle upon the machine, sets the machine in operation, and removes the bundle therefrom after the tying operation is completed;

In a prior, more advanced tying apparatus from the standpoint of automated operation disclosed and claimed in US. Patent No. 3,085,501 to Glen E. Wimmer dated April 16, 1963, a conveyorized system brings untied bundles of mail to the first of two tying machines which ties the bundle with a long tie, 'andthen transfers the bundle to the second machine which ties at cross tie around the bundle, after which the bundle is ejected from the machine and dropped into a hopper. The use of two tying machines reduces the total tying time for each bundle, in that while a long tie is tied around one bundle, a cross tie is tied on a preceding bundle, whereas in the prior apparatus the cross tie and long tie were effected suc cessively on the same machine.

in the system disclosed in the aforesaid co-pending application automatically operated apparatus is used to pick a bundle of envelopes to be tied from a moving conveyor and transfer it to the first tying machine. An additional transfer mechanism was required to remove a tied bundle from the first machineand transfer it to the second machine. These transfer mechanisms used an airoperated clamping device for seizing and moving the bundles from the conveyor to a tying machine and required, in addition, precise timing of the transfer mechanisms relative to the operation of the conveyor and the first and second tying machines, all of which increased the complexity of the apparatus, its initial cost, and the cost of servicing and maintaining it in operation.

rates Patent 0 It is accordingly a principal object of this invention to a provide a conveyorized system for tying a long tie and a cross tie on a bundle of mail or the like, which system is less complicated than any system heretofore proposed, which is less expensive in its initial cost, and is simpler to maintain in operation.

Edhhfidh Patented Dec. 8, 1%64 Another object of this invention is to achieve simplicity in a conveyorized system for tying bundles of mail or the like, by elfecting a tie around a bundle of mail while said bundle remains on a moving conveyor;

As a more specific object, this invention has within its purview the provision of a means for releasably compacting a bundle of mail while it is on a moving conveyor, so that the compacted bundle may be effectively tied While it is on the conveyor,

Yet another object of this invention is the provision of a system for tying bundles of mail which includes the step of tying a bundle of mail while it is in motion on a conveyor, the tying means, however, being substantially standard and readily replaceable and serviced in the event of its failure.

These and other objects of this invention will become apparent from the following, detailed description of a preferred embodiment thereof when taken together with the accompanying drawings in which FIG. 1 is a schematic plan view of a conveyorized apparatus for tying bundles of mail, said apparatus being made in accordance with this invention;

FIG. 2 is a fragmentary, more detailed plan view of a portion of the conveyor used with the system of FIG. 1;

PEG. 3 is a fragmentary end elevational view in section, on an enlarged scale of a conveyor such as that shown in FIG; 2, the view being taken from the left-hand end of the conveyor as viewed in that figure.

FIG. 4 is a fragmentary front elevational view, partly in section and on an enlarged scale of a portion of a clamping means for a bundle of mail used on the conveyor of FIG. 2, the section being taken along line 44 of FIG. 3;

FIG. 5 is a fragmentary plan view on an enlarged scale of the compacting means used with a bundle to be tied while said bundle is on the conveyor of FIG. 2;

FIG. 6 is a fragmentary front elevational view, on an enlarged scale and partly in section, of the support for a portion of the compacting means of FIG. 5, said FIG. 6 being taken looking in the direction of the arrows ti6 in FIG. 5; V

FIG. 7 is a fragmentary front elevational view, substantially on the scale of FIG. 6, of the transfer mechanism by which a tied bundle is removed from the conveyor of FIG. 2 to a conveyor which moves the bundle to the second tying machine of the system;

FIG. 8 is a fragmentary front elevational view corresponding to FIG. 7, but showing a bundle of mail and the conveyor in a later stage of operation;

FIG. 9 is an enlarged end elevational view of the system of FIG. 1, the view, being taken in the direction of the arrows 99 of FIG. 1.

FIG. 10 is a fragmentary plan view, on a reduced scale with respect to FIGS. 7 and 8, of the transfer mechanism and conveyor system for moving a bundle from the conveyor of FIG. 2 to the second tying machine;

PEG. 11 is a fragmentary elevational view of the conveyor mechanism for moving a tied bundle from the first conveyor mechanism of FIG. 2 to the second tying machine, the elevation being taken in the direction of the arrows 11-41 on PEG. 10.

FIG. 12 is an enlarged side elevational view of a fragment of thechain of the conveyor shown in FIG. 11; and

FIG. 13 is a schematic wiring diagram for the controls and motor operated mechanisms used in the system of FIG. 1.

The principal elements of thesystem of this invention are shown in FIG. 1 in schematic form and comprise a substantially horizontally disposed conveyor 20, which may be disposed in an aisle located between series of sorting stations 21 and 22, where incoming mail is sorted by hand according to destination. The Sorters segregate the mail into bundles of similarly oriented envelopes which are then placed upon conveyor in such mannerthat the bundles rest upon the long edges of the envelopes of which they are comprised. Several such bundles 23, 24 and 25 are shown schematically on conveyor 29. Said conveyor moves from left to right as seen in FIG. 1, past a tying machine 26, the operation of which is initiated by a trip device contacted by a moving bundle such as 25. Tying machine 26 is designed to produce a long tie around a bundle 25 while said bundle is in motion 'on conveyor 20. A clamping device, hereinafter to be described, compresses one end of said bundle and a compacting device 27 compresses the opposite end of said bundle while the latter is being tied, the compacting device being designed to move with the bundle on the conveyor during the tying operation.

A tied bundle 28, after passing tying machine 26, is removed from conveyor 20 by a stripping device 29, which allows the bundle to slide down upon a table 36] forming part of a transfer device 31, located at the right hand end of conveyor 2!), as seen in FIG. 1. Transfer device 31 is designed to propel a bundle 32, which has been removed from conveyor 20 and slid upon table 36, in a direction transversely to the direction of movement of conveyor 26, and upon the table 33 of a second tying machine 34, The function of which is to tie a cross-tie around a bundle 35 resting upon table 33. The operation of 'the second tying machine 34 is initiated in part by the presence of a bundle, such as 35, on table 33 thereof. From second tying machine 34'the bundle is ejected into a hopper or any other suitable device (not shown) designed to store the tied bundles or to initiate their movement into the desired flow pattern for the mail.

Conveyor 20 is shown ingreater detail in FIGS. 2 and 3, and is comprised of a frame 36, which includes a series of spaced upright angle iron supports 37 disposed in pairs along said conveyor, said upright angle irons 37 supporting upper cross plates 38 and lower transversely disposed angle irons 39. To the upper cross plates 38 are secured spaced longitudinal angle irons 40 and 41, each of which supports a track 42 and 43, respectively. Said tracks are in the form of continuous plates having upper surfaces 44 and 45 for supporting the moving elements of'the conveyor. Also suitably supported from frame 36, by means not shown, is a longitudinal plate 46 which, as will be hereinafter described, provides a support for bundles of mail moved by the conveyor and prevents said bundles, or the elements thereof, from falling through the moving conveyor into the framework 36.

The moving portion of conveyor 26 is comprised of a pair of endless chains 47 and 48, which are disposed parallel to one another and pass over sprockets 49 and St) disposed on the left hand end of the conveyor as viewed in FIG. 1, and mounted on a common shaft 51 supported in space bearings 52 and 53 on vertical frame supports 37.

Certain of the links of the chains 47 and 43, such as, for example, every fourth link, is of T form as shown in FIG. 4, the tail 55 of the T overlying the sides of the tracks 42 and 43 and thus constraining the chain to ride on, and follow, said tracks. It is contemplated, as shown in FIG. 3, that the tails of the T links on two sides of a chain will embrace a track and thus prevent the chain from moving laterally withrespect to said track.

In view of the long span of the conveyor, and, therefore, of the relatively long portion of the chain which is passed underneath the operative side of the conveyor to return to said operative side, suitable support for said chain is desirable to prevent it from swinging too low and possibly becoming misaligned with the sprockets at the beginning end (left hand end as viewed in FIG. 1) of the conveyor. The requisite support for the returning portion of the conveyor is provided by longitudinally disposed, box-type structural members 56 and 57 which are spaced to lie directly below tracks 42 and 43, and are secured to transverse angle irons 39. The bottom surface of each of the structural members 56 and 57 is slotted and the ends of the slot are then bent inwardly of the memberas shown at 58 and 59 to form spaced longitudinal rails. The links of chains 47 and 48 intermediate those having the T link, such as 54, are also provided with T links, but the tails of the T are bent outwardly of the chain, as shown at 60 and 61, to overlie and ride upon the inwardly turned ends 58 and 59 of the structural member. The laterally turned tails 60 and 61 of the links of the chains 47 and 48 therefore serve to support the chains and their attached letter holding clamps (hereinafter to be described) from the boX structural members while said chains are returning to the entrance or beginning end of the conveyor 20.

It is desirable that the bundles of mail be presented to the tying machines, particularly to the first tying machine, in an orderly and predetermined fashion. It is particularly desirable that the bundles be compacted and held in a compacted condition during the tying operation to avoid the formation of loose ties. These requirements are met by the clamping devices shown in FIGS. 2, 3 and 4. Said clamping devices are arranged in pairs 62 and 63, the devices 62 all being disposed at stated intervals on chain 47 and the devices 63 being disposed in aligned relation to the devices 62 on chain 48. Inasmuch as chains'4'7 and 48 are driven from sprockets mounted on the same shaft and rotatable, therefore, at precisely the same speed, clamping devices 62 and 63 will always be correctly aligned.

The clamping devices 62 are comprised of two parts 64 and 65, each mounted on horizontally extending portions 66 and 6'7, of certain of the links of chain 47. The parts 64 and 65 are mounted on different links so that as the chain passes over a sprocket, said parts can move independently and can separate as required by the geometry of the rotating sprocket and chain. This separation is utilized to release a bundle as it leaves conveyor 20, as will be described more fully hereinafter. Part 64 has a horizontally disposed plate 68 and a vertically disposed plate 69, said horizontally disposed plate 63 serving as a support for the ends of the bundle and the vertically disposed plate 69 serving as an abutment against which the bundle is to be compressed.

Part 65 has a horizontal plate 70 to the forward portion of which is secured a bracket 71 to which, in turn, is secured a vertically disposed leaf spring 72 curved inwardly of the conveyor and designed to have its curved end 73 bear against vertical plate 69 on part 64.

Clamping device 63 is similarly comprised of two parts '74- and 75 which are secured to chain 48 through horizontally disposed portions 76 and 77 on separate links of said chain. Parts 74 and '75 are independent of one another, part 74'being comprised of a horizontal plate 78 and a vertical plate 79, and part 75 being comprised of a single substantially rectangular plate 86. Horizontal plate 78 serves to support the ends of a bundle, as does also plate 80, and the vertical plate 79 serves as an abutment for pressure device 27, which compacts the ends of the bundle extending over clamp part 63.

In FIG. 2 the bundle 24 is shown held by the clamping device portion 62. It may be observed that leaf spring 72 has been considerably deformed to exert a pressure upon bundle 24 in the direction of the vertical plate 69 to hold one end of the bundle in a compacted condition. The opposite end, that is, the one cooperating with the clamp part 63 is at this stage uncompressed. The means for compressing this end of the bundle will be hereinafter described.

The uniform presentation of a bundle to the first tying machine requires, not only that the bundle lie against the clamp parts 62, 63, but also that the ends of the bundle be disposed at a predetermined position on the conveyor, particularly the end at which the knot is to be until the end of the bundle abuts against rail 32.

tied by the tying machine. To facilitate in locating said end of the bundle at said predetermined position, the conveyor Zil is provided with horizontally extending brackets 81 (PEG. 3) of 2 cross section, one leg of which is riveted or otherwise secured to angle iron 4t) and the other leg of which serves to support a continuous rail 82. A bundle 24 is inserted into a clamping device part 52 and is pushed horizontally against leaf spring '72 and laterally against vertical plate 69 on part 64, thereby distorting leaf spring 72 and moving it away from the vertical plate 69 to form an opening through which said bundle may be pushed The said rail 82 thus definitely locates the one end of the bundie relative to the conveyor and to the first tying machine the position of which is fixed relative to conveyor 20.

The means 27 for compacting the end of the bundle which overlies clamp part 63 will now be described in detail. Said means is disclosed in FIGS. 5 and 6, and is comprised, in general, of a star shaped wheel 27 mounted on a laterally extending bracket'83 secured by Welding or otherwise to longitudinal angle iron il. Said wheel 27 is comprised of four spring fingers S4, 35, 6 and 87, of

identical form, each having a substantially fiat attaching end 88 secured by a pair of bolts 89 to a square hub 91?. The remainder of each spring finger 84- to 87 extends substantially radially'outwardly from the attaching end 38 and terminates in a curved region designed to contact the relatively free end of a bundle such as 24 and compress said free end against the vertical plate 79 on part 74 of the clamp 63.

Hub 90 is secured to a shaft 92 which passes through an elongated bearing d3 having a flange 94 at the lower end thereof as viewed in FIG. 6, the flange resting upon the free end of bracket 83 to which it is secured by bolts 95. Shaft 92 is free to move axially in bearing 93 and to this end is provided with an abutment $6 which may take the form of a washer held in place by a nut 97 on the threaded lower end of shaft 92, said abutment 96 being axially spaced from a washer 98 abutting upon the underside of brack S3. A helical spring 99 is compressed between abutment 96 and washer 98 and serves to exert a downward axial force upon shaft 92.

The requisite compacting force for bundle 24 at clamping part 63 is provided by interposing a resistance to the rotational movement of start wheel 27 so that as the conveyor moves from left to right as viewed in FIG. 5, bundle 2-!- will contact one of the spring fingers 34, 35, 85, or 87 and then will attempt to turn the star wheel. It is understood that the number of fingers is so selected that only one such finger will be interposed in the path of movement of a bundle at a time to avoid any interference between the fingers and bundle. The requisite resistance to rotation of star wheel 27 is provided by a brake device 100 operative between the star wheel and bearing 93. Said brake device is comprised of a brake surface liil on the underside of hub 99 and a corresponding brake surface 162 on the upper end of bearing 93 which cooperate to gether to produce a frictional resistance to the rotation of star wheel 27. The downward force exerted by spring 99 on shaft 92 causes surfaces fill and M2 to be engaged with one another at all times. The amount of such force can be varied by adjusting the position of nut 97 on shaft 92. The brake surfaces 161 and N2 may also be formed on appropriate brake material fastened or adhered to one or both of the brake members, hub 90 and the upper end of bearing 93. I

The first tying machine 26 is a substantially standard tying machine, such as is shown in B. H. Bunn Patent No. 2,898,847 dated August 11, 1959. It has been modified, however, to eliminate a table since the bundle to be tied is already supported during the tying operation upon conveyor 29. The machine has also been modified in that it is turned 90 from the horizontal and hence lies on its side. It is not believed necessary for the purposes of this invention to describe the details of the machine,

such details being given in the aforesaid Bunn patent. Sufi'ice it to say that said machine is provided with a twine arm 193 (FIG. 1 and FIG. 9), which rotates about a vertical axis lildin a counter-clockwise direction as viewed in FIG. 1. It may be noted that with the conveyor moving from left to right'as viewed in FIG. 1, and twine arm 1% rotating in a counter-clockwise direction, the movement of the twine tends to compress a bundle against star wheel 27 and hence assists in making a tight knot. The vertical dimension of the clamping devices for the bundle is no greater than and preferably somewhat less than one-half the vertical dimension of the bundle, so that the clamping means for the bundle does not interfere with the movement of the twine around the bundle and the tying of the knot.

It may be apparent that as the bundle moves past tying machine 26, star wheel 27 is compelled by the bundle to rotate and that eventually'the spring finger 84, 85, 86 or 87 contacting the bundle will be rotated out of the way of the bundle. In so doing, the bundle will rotate the adjacent finger in a clockwise direction, as viewed in FIG. 5, into the path of the next bundle. The said adjacent finger will then be in readiness to perform its compressing function upon the next bundle and to be, in turn, rotated out of the way by said next bundle after it is tied.

The removal of a bundle from the conveyor 20 to the table 3% of the transfer device 31 is eifected by the means shown in FIGS. 7 and 8. Althoughin the horizontal position of conveyor 20 the two parts 64 and 65 of clamping device 62 and the two parts 74 and. 75 of clamping part 63 are adjacent one another, as the clamps move over to the opposite end of the conveyor and upon the sprockets 105 and 1% (FIGS. 7, 8 and 10) located thereat said parts of the clamping device and part will begin to separate as shown in FIGS. 7 and 8, thereby freeing a bundle such as 28 therefrom.

' It may be observed from FIG. 10 that sprockets 106 and 197 are mounted on a shaft 108 appropriately supported in bearings on frame 36 so as to be rotatable together. Said shaft ltlS is driven through a sprocket 109 and chain lltl from a sprocket E11 (FIG. 9) and a slip clutch 112 driven by a motor 113 mounted on frame 36.

The means by which a bundle 23 is transferred from conveyor 2% to table Stl comprises a cam plate 114 (FIGS. 7, 8, 10) which is secured at one end to longitudinal plate disposed between the chains 47 and 48. Its other end as viewed in FIGS. 7 and 8, is bent downwardly as at 115 and then horizontally at 116 where it is secured to the underside of said table 30. As the clamping device passes around a sprocket 106 or 107 the two parts of the clamping device 64, for example, separate, but the vertical platesbil and 79 still contact the bundle 28. Said vertical plates therefore continuously urge a bundle 28 forward and cause it to transfer from horizontal plate 46 to cam plate 114 over which the bundle then rides, as shown in FIG. 8. Cam

.plate ll lis curved downwardly so that initially bundle 28 is urged along the cam plate by the vertical plates. At about the point when the vertical plates are no longer in contact with the bundle, said bundle 23 will slide down the cam plate 114 by gravity and be rotated by said cam plate so that it will fall upon table '59 on its side as viewed in FIGS. 7 and 8. Thus, although a bundle may start on conveyor 2b with the edges of the envelopes contacting the conveyor and the planes of the envelopes disposed in a generally vertical direction, said bundle will be turned through in its transfer from conveyor 2%) to table 343 and will lie on said table 30 on its side.

With a bundle, such as 32 on table 3!) the next step is to transfer said bundle to the second tying machine 34 where a cross-tie canbe tied. The transfer mechanism is shown in FIGS.9, l0 and 11 and is comprised of an endless chain 117. Sprocket 121 is the drive sprocket and is driven from a bevel gear 122 which, in

turn, is driven by a mating bevel gear 123 mounted on a shaft 124 supported in bearings 125 and 126 from a plate 127 secured to the frame 36 of the machine. Shaft 124 is driven by a sprocket 128 and chain 129 from a drive sprocket 136 rotatable with sprocket 111 and'driven through slip clutch 112 from the same motor 113.

Curved drive fingers 131 and 132 are secured through horizontal extensions 133 and 134 respectively to chain 117 so as to be driven thereby. The support for the fingers is shown in FIG. 12, and comprises a bearing 145 mounted on an extended pin 146 constituting a pivot for adjacent links 147, 148 of chain 117. On said bearing 145 is oscillatable a plate 149 to which the horizontal extension 133 for supporting a drive finger 132 is secured. Chain pins 159 and 151 on either side of pin 146 are extended so that they pass under plate 149 and contact, during straight-line movement of the chain, surfaces 152, 153 on plate 149. Thus, during straight-line horizontal movement of said chain 117, rotation of a finger 132 about its bearing 145 is prevented by the contacting of plate 149 withpin 150.

Fingers 131 and 132 are designed, as shown in FIG. 7, to contact the end of a bundle 32 and to move said bundle from table 30 to the'table 33 on the second tying machine 34. Chain 117 moves in a clockwise direction, as viewed in FIG. 9, so that a drive finger moves horizontally until it reaches the upper sprocket 119 at which point the chain begins to pass around said sprocket and finger 131 is rotated clockwise. This meansthat finger 131 is halted in its movement toward the second tying machine 34 and then begins a reverse and upward movement until it is turned 90, after which it moves downwardly toward spnocket 121, through a slot 184 in table 30, and then under table 30, and back tothe left, as viewed in FIG. 9. It passes around sprockets 120 and 118, each sprocket turning it 90, and it returns to a vertical bundle-driving position, as shown in FIG. 9.

It is important that the fingers 131, 132 are so re-' lated to the chain from which they are supported and by which they are moved, that in passing around a sprocket they do not give a bundle of mail an additional impulse but, on the contrary, simply cease moving the bundle forward and leave it at its most advanced position. In other mechanisms driven by chains which pass over sprockets, the device attached to such chain and used to propel an article normally gives the article an additional impulse as it passes around a sprocket, and such additional impulse, in the present instance, would be undesirable, inthat it would tend to toss a bundle beyond the point at whichthe second tying machine is operative to efiect its second or cross-tie.

In view of the cantilever construction of the finger supporting extensions 133 and 134 and the eccentric forces which might be imposed thereuponby the resistance of a bundle 32 to forward movement, a pair of opposed flat horizontal guides 135 and 136 supported by straps 137 and 138 from frame 36 are used to lend additional support to the extensions 133 and 134 during their operative or driving movement. The entrance ends of ,guides 135 and 136 are curved to diverge from one another to facilitateentry of the extensions 133 and 134 therebetween.

It is desirable that the curved drive fingers 131 and 132 contact the lowermost envelope of a bundle toavoid putting such lowermost envelopes out Of line with the rest of the bundle. To'this end, table 311 is provided with agroove 139 to allow the end 140 of a drive finger 132 to extend down below the envelope-supporting surface of table 30, said groove 139 extending the length of table 30 in the direction ofmovement of fingers 131 and The second tying machine 34 may again be of any of the standard forms presently commercially available. The one selected to illustrate this invention is of the type known as a ring tie machine and is disclosed in B. H. Bunn Patent No. 2,471,304 dated May 24, 1949. Said 5% machine, as stated previously, is'provided with a table 33, upon which a bundle, such as 35, is pushed by the transfer mechanism 31. As is customary, however, a comp-acting mechanism is provided for holding the bundle firmly against table 33 while the cross-tie is being made. The details of the compacting mechanism are not material in this invention and hence will not be given herein. The compacting mechanisr however, may be of the type shown in B. H. Bunn Patent No. 1,606,290, dated November 9, 1926, and incorporates a clamp 141 secured to a vertically reciprocable rod 142 appropriately driven in timed relation to the operation of the tying machine, so that pressure is exerted by clamp 141 on a bundle 35 while the tying machine isin operation. The

twine arm for the machine is shown at 143, and as explained in the aforesaid Bunn Patent No. 2,471,304, it is driven by a ring from which the machine gets its name, and the tied bundle is then ejected through the ring to the opposite side of the machine.

The controls for the system comprise a mechanical trip 154 shown on FIGS. 1 and 5 and adapted to operate the standard trip for tying machines of the type as shown at 26 in FIG. 1 (see B. H. Bunn Patent No. 2,898,847), and a plurality of micro switches, which are shown schematically in FIG. 13, together with the devices controlled thereby. In addition, certain manually operated switches are also employed, as also shown schematically in said FIG. 13. The electrical motors used in the system comprise the aforesaid conveyor motor 113 and individual tying machine motors 155 and 156, motor 155 being used to operate tying machine 26 and motor 156 being used to operate tying machine 34. Fused switches 157 and 158, manually operated, control the operation of motors 155 and 156, respectively. The power for motors 113, 155 and 156 is derived from a 3- Wire 220 volt, 3 -phase Y-type line shown at 159, said line 159 being connected through a fused switch box 161) and a master start-stop switch 161 to motor 113. A 110 volt tap 166 is taken from switch box 160 and used to power tying machine motors 155 and 156 and the control circuit for the second tying machine 34.

In series with the start switch 161 is atwine tension switch 162 which is operated by the twine 163 (FIG. 1) as it leaves the twine tensioner of the machine, shown schematically at 164 in FIG. 1. It is contemplated that should the twine in the first tying machine 26 either break or run out, the entire conveyor will be immobilized to avoid feeding untied bundles of mail to the transfer device 31 where such untied bundles would be scattered and would be a source of great inconvenience and delay in retrieving the scattered mail, not to mention possible damage thereto.

The second tying machine 34 is controlled by a solenoid operated trip rather than by a mechanical trip operated by a bundle as in machine 26. The solenoid is shown schematically at 165 in FIG. 13 and is adapted to be energized from the 110 volt line 166. A master switch 167 of .the fused variety is manually operated and comprises a master control for the energization of relay 165. It is connected to one side of 110 volt line 166. Intermediate manual switch 167 and solenoid 165 is connected a latching relay shown generally at 168, said latching relay including an energizing coil 169, anarrnature 170, and a reset coil 171. Armature 170 is adapted to be latched in operative position until released therefrom by the reset coil 171. Said latching relay is of standard deslgn and hence the details of construction thereof will not be described herein.

Armature 170 operates a single throw double-pole switch, one'pair of contacts of which is shown at 172 and the other pair of contacts of which is shown at 173. One of the contacts of the pair 172 is connected to a line 174 from switch 167 and one of the contacts of the pair 173 is connected to a line 175 which, in turn, is connected through a pair of switches 176 and 177 in series to the other side of the 110 volt line 166. Switch 176 is a microswitch which, as shown in FIG. 1, is mounted on tying machine 34 in the path of a bundle 35, so that when a bundle is in place in machine 34 in position to be tied thereby, said switch 176 is closed. Switch 177 is mounted on the guide 135 of transfer conveyor 31 and is adapted to be operated by one of the horizontal extensions 133 or 134 for the drive fingers 131 and 132 respectively (FIG. It will be appreciated that switch 175 is operated just as soon as the forward edge of a bundle 3S begins to pass said switch, but at this point the bundle is not properly located on tying machine 34 for a tying operation and, accordingly, operation of the tying machine is delayed until the bundle is fully advanced. This point is determined by the position of the finger 132 (FIG. 10), which may be pushing sm'd bundle, and said finger 1 .32 is at its foremost position when it reaches and begins to go around sprocket 119. When both switches 176 and 177 are made, solenoid 165 is energized through the pairs of contacts 172 and 173 and the mechanical trip on machine 34 is operated to commence the tying operation.

It is necessary, of course, to reset relay 168 so that solenoid 165 is de-energized and the trip which controls the operation of tying machine 34- is released. The resetting operation is controlled by a switch 178 which, as shown in PEG. 1, is located on the frame of tying machine 34 in such position that its operative element is in the path of movement of a short projection 179 at the rear ofthe twine arm carrying ring of tying machine 34. The exact location of switch 17 8 is not critical, it only being necessary that said switch be operated by projection 179 after the ring on which said projection is mounted has been set in motion by the operation of the trip mechanism controlled by solenoid 165.

The reset coil 17?. of the relay 168 is connected,"through a line 180, to switch 167, and one side of the 110 volt line 166 and the other side of the coil 171 is connected through a line 181 and switch 173 to the other side of said 110 volt line 166. Thus, after the twine arm has been set in motion, the latch of the latching relay 158 is released to restore the relay to the condition shown in FIG. 13 wherein switch contact pairs 172 and 173 are open and solenoid 165 is de-energized. This allows the trip mechanism in the second tying machine 34 to return to the condition wherein it is adapted to halt the operation of the twine arm until said trip mechanism is again operated by solenoid 165. As described in the aforesaid Bunn Patent 2,471,304, the trip mechanism will not halt the operation of twine arm until a complete tying cycle has been efiected.

The operation of the device is as follows:

Bundles of mail which have been sorted, such as are shown at 21 and 22, are manually placed upon conveyor and pushed from the-star wheel side of the conveyor into clamping device 62-against the resistance of leaf spring 72 which clamps the inserted end of the bundle against vertical plate 69 to compress and hold firmly said bundle in clamp 62. The bundle is urged through said clamp 62 until it contacts rail 82 which serves to align the ends of the envelopes making up the bundle. As the conveyor and its bundles move to the right as viewed in FIG. 1, a bundle will strike one of the fingers 84, S5, 86, or 87, of the star wheel compacting device 27, which, because of the resistance to rotation produced by brake 1%, (FIG. 6) presses the end of the bundle disposed on clamping device 63 against vertical plate '7? on part 74 of the clamping device 63 and will hold said end against the vertical plate 79 during the travel of the bundle past star wheel 27. Shortly after contacting said star wheel and becoming compacted at its-star wheel end the bundle Will contact the mechanical trip 154 of tying machine 26 which, as described in the aforesaid Bunn Patent No. 2,898,847 starts the twine arm 1% to rotating and effects the tying of the bundle with a long tie. As stated previously, the vertical height of the spring 72 and of the vertical plates 69 and 79 is less than the height of the bundles so that the twine may be wrapped around the bundle Without interference with the clamping device. If, at any time, however, twine 163 breaks or runs out so that there is no tension in the section between the twine tensioner 154 and the twine arm 1%, the twine tension switch 162 will open and will stop the operation of the entire apparatus including conveyor 20, transfer device 51, and both tying machines 26 and 34.

After the bundle has moved past tyin machine 2 5 and received'a long tie, it will have moved the compacting device 27 around so that the next spring finger thereof will project into the path of the succeeding bundle and be in readiness to perform its compacting function thereon.

The moving bundle with its long tie then reaches the right hand end (FIG. 1) of conveyor 26 where the conveyor begins to pass around sprockets 1% and $7 while the central portion of the tie bundle engages the stripping device 29. The passage of the conveyor around these sprockets opens the clamping device, as shown in FIG. 7, to free the tied bundle, and the bundle then slides along the downwardly curved cam plate 1.14 and is turned there by through substantially as it falls off said cam plate 114 upon table 39. It now lies upon its side and is in position to be advanced by the transfer device 31 into the second tying machine. With the transfer device 31 operating, one of its curved drive fingers 132 will contact the rear of a bundle, as shown in FIG. 7, and will start to move saidbundle along table 39 toward the second tying machine 34. As the bundle begins to move along table 39, however, it actuates switch 183, which energizes the coil Th9 of latching relay 168 and closes the pairs of contacts 172 and 173. Solenoid 165, however, is not yet energized since switches 176 and 177 must still be closed to complete the circuit through said solenoid. The preceding bundle is completing its tie and will be released from its clamp to allow the oncoming untied bundle to push it through the machine and into a waiting rcceptacle. As finger 132 .moves along the upper horizontal portion of the trmsfer device towmd sprocket 19 the bundle will engage the switch 170 to close the contacts thereof, thus leaving only switch 177 open to restrain the operation of solenoid When the finger reaches sprocket 119, it also engages said switch 177 to close its contacts and thus complete the circuit through solenoid 165, which then is energized to operate the trip mechanism on the second tying machine 34 to set it in operation. Finger 132 does not advance any further and is then brought around sprocket 1119 downwardly through the slot 184 provided for that purpose in table 34 As it rounds the sprocket 119, it allows switch 177 to be opened, thereby tie-energizing solenoid 165. This, in turn, allows the trip mechanism which had been operated in tying machine 34 to reset itself for the next operation after the tving operation is completed. It isunderstood that the clamping device will be automatically brought down upon the bundle, held there while the bundle is being cross-tied, and then will be raised to release the bundle for movement through the machine by'the succeeding untied bundle.

In the event that there is no bundle on table 3%, but

a bundle is passing the first tying machine 25 so that conveyor and transfer mechanism 315. are in operation, switches 176 and 183 will not be operated and, accordingly, the second tying machine 34 will not be set in motion needlessly. It may also be apparent that if an emptyclarnping device 62 should pass trip 1% of the first tying machine 26, said trip will not be operated because the empty clamping device will pass under the trip and hence the tying machine will not be set in motion. Furthermore, since conveyor 26 and transfer device 31 are driven through sprockets and chains from the same motor 113 and shaft, said conveyor and transfer device will always be operated in synchronism with one another so that a finger 132, for example, will not be moving across table 30 while a bundle is falling thereon.

Thus, by the foregoing apparatus, it is possible to tie simultaneously a long tie on one bundle of mail or the like and a cross tie on another bundle, thereby increasing the number of bundles that may be tied per unit time. The tying machines used are substanti ly standard, modified largely by a mere removal of urmecessary parts to adapt them to the conveyorized handling of the mail. This means that repairs and replacements for the machines are very readily made and, in fact, spare machines may be kept onhand to take the place of a machine on the conveyor requiring repairs. This reduces down time and results in the least interruption in the mail handling operation. 7

It is understood that the foregoing description is merely illustrative of a preferred embodiment of the invention and that the scope of the invention, therefore, is not to be limited thereto, but is to be determined by the appended claims.

I claim:

1. Apparatus for tying envelopes or the like into bundles, said apparatus comprising a continuously moving substantially horizontal conveyor, means on the conveyor and movable therewith for supporting a bundle independently of other bundles on the conveyor in such manner 7 2. Apparatus for tying envelopes or the like as dc scribed in claim 1, said means on the conveyor and movable therewith for supporting a bundle comprising transversely spaced clamps on the conveyor adapted to contact the lower end regions of the bundle to compact said end regions While said bundle is being tied by the bundle tying means, the upper regions of the bundle being free to receive said reach of twine.

3. Apparatus for tying envelopesor the like into bundles, said apparatus comprising acontinuously moving conveyor, means on the conveyor and movable therewith for supporting a bundle in such manner that the planes of the envelopes are at right angles to the direction of movement of the conveyor, means adjacent said conveyor for tying a reach of twine around said bundle while said bundle is supported on the moving conveyor, a second tyingmachine for tying said'bundle crosswise of the tie ma'de'by the first said tying machine, a table adjacent the end of the conveyor, stationary means in the path of movement of the bundle for stripping the bundle from the moving conveyor, said stationary means having a vertical section adjacent the table along which the bundle drops by gravity upon the table, and continuously movable transfer means on the table and synchronized with the said conveyor for moving a dropped bundle from the table to the second tying machine.

4. Apparatus as described in claim 3, said stripping and dropping means comprising a plate having a section adjacent the conveyor which'terminates in a downwardly sloping plane adapted to be contacted by a bundle on a conveyor while said bundle is supported on said conveyor, and means for changing the direction of movement of the conveyor relative to the curved plate such that said moving bundle is stnipped from the conveyor by said plate, said plate having a vertical terminal portion adjacent the table and connected to the end of the downwardly sloping plane to form an abrupt dropoif whereby to cause said bundle to turn and drop on the said table with the planes of the envelope substantially parallel with the plane of the table.

5. Apparatus for tying envelopes or the like into bundles, said apparatus comprising a continuously moving substantially horizontal conveyor, means on the conveyor and movable therewith for supporting a bundle in such manner that the planes of the envelopes are at right angles to the direction of movement of the conveyor, means adjacent said conveyor for tying a reach of twine around said bundle in a substantially horizontal plane while said bundle is supported on the moving conveyor, means for tying a reach of twine around said bundle crosswise of the'first tie, a transfer mechanism operable in synchronism with the conveyor, stationary means in the path of movement of the bundle for stripping a bundle from the first conveyor, means for turning a stripped bundle and ,planes of the envelopes thereof are substantially horizontal, said stationary means comprising aplate having a downwardly sloping section and a vertical section adjacent to and intersecting the downwardly sloping section and said bundle being turned by falling'along'said vertical section, and means on the transfer mechanism for pushing a dropped bundle upon the cross tying means and a crosstied bundle oil the said cross tying means.

References Cited in the file of this patent UNITED STATES PATENTS 

1. APPARATUS FOR TYING ENVELOPES OR THE LIKE INTO BUNDLES, SAID APPARATUS COMPRISING A CONTINUOUSLY MOVING SUBSTANTIALLY HORIZONTAL CONVEYOR, MEANS ON THE CONVEYOR AND MOVABLE THEREWITH FOR SUPPORTING A BUNDLE INDEPENDENTLY OF OTHER BUNDLES ON THE CONVEYOR IN SUCH MANNER THAT THE PLANES OF THE ENVELOPES ARE AT RIGHT ANGLES TO THE DIRECTION OF MOVEMENT OF THE CONVEYOR, SAID ENVELOPES HAVING AN UPPER PORTION WHICH PROJECTS ABOVE SAID SUPPORTING MEANS, AND MEANS ADJACENT SAID CONVEYOR FOR 